JPH0682536A - Method and circuit for performing combination test on circuit breaker - Google Patents

Abstract

PURPOSE:To obtain a method and circuit for performing a combination test with high equivalence without causing excess stress. CONSTITUTION:A voltage source transformer 11 is inserted into the first interruption phase of an auxiliary breaker 4 similarly to second and third cut-off phases and an isolation switch 12 is inserted between the first cut-off phase of a sample circuit breaker 3 and a voltage source circuit 2. In such constitution, a transient recovery voltage appears immediately after cut-off of voltage source current but since the isolation switch 12 isolates the voltage source circuit 2, an AC voltage is applied from the voltage source transformer 11 onto the cut-off phase of the sample circuit breaker 3. This constitution suppresses voltage rise with respect to other phase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an equivalent synthetic test method for circuit breakers, and more particularly to a three-phase synthetic test method and a test circuit for realizing this method.

[0002]

2. Description of the Related Art As the circuit breakers become higher in pressure and capacity,
As the verification means, a synthetic test (equivalent synthetic test) is performed instead of the direct test. In this test, a current source that supplies a large current at a low voltage and a voltage source that supplies a small current at a high voltage are coupled and switched immediately before or after the interruption instant. Further, in the three-phase all-in-one circuit breaker, a test method considering the interaction between the phases is required due to its characteristics, and various three-phase synthetic test methods have been proposed. For example,
A three-phase synthesis test method using a synthesis test circuit configured as shown in FIG. 4 has been proposed.

In FIG. 4, 1 is a current source circuit for supplying a short-circuit current, 2 is a voltage source circuit for the first interruption phase using the current superposition method (Wild-Piquette method), 3 is a circuit breaker under test, and 4 is an auxiliary circuit. It is a circuit breaker. Further, 5 and 6 are voltage source transformers for the second and third cut-off phases, respectively, which use the Skeitz method. Reference numerals 7 to 9 are elements for adjusting transient recovery voltage (TRV), and 10 is a circuit for extending the arc period.

In this synthetic test method, the first shut-off phase is the thermal shut-off performance and the gap between the circuit breakers by the Wild Pique method,
The purpose of this is to provide insulation performance between the ground and the second and third cutoff phases using the Skeitz method to verify the insulation performance between the cutoff phase and the ground.

Next, the synthetic test method will be described with reference to FIGS. 5 and 6.

First, a short-circuit current is supplied from the current source circuit 1 while the test breaker 3 and the auxiliary breaker 4 are closed (point a). At the time when the phase to which the voltage source circuit 2 is connected is controlled so that the first phase is interrupted in the intended arc time, the test breaker 3 and the auxiliary breaker 4 are opened. Immediately before the zero point of the intended first-phase breaking current, the voltage source current is superimposed from the first breaking-phase voltage source circuit 2 (point b). After that, the superimposed current is cut off (point c). At the same time, the transient recovery voltage is generated by the voltage source circuit 2 for the first cutoff phase and the TRV 9, and the first phase cutoff is completed.

The short-circuit current, which has subsequently become a single-phase series circuit, is interrupted by the other two phases (point d), and the voltage source transformers 5 and 6 for the second and third interruption phases and the respective secondary side resistors R ₅ , R ₆ generates a transient recovery voltage in the other two phases and completes all-phase cutoff.

[0008]

A drawback of this conventional synthetic test method is that the recovery voltage immediately after interruption has a significantly higher interphase voltage than the direct test method.

That is, in the case of the conventional synthetic test method, since the wild picket method is used to verify the first cutoff phase, the recovery voltage of the first cutoff phase is clear from FIG. 7 in the case of the non-grounded system test. In this way, the DC voltage becomes constant. The recovery voltage value V at this time is V = √2 × 1.5 / √3 × E = 1.
22E (E is the rated voltage of the circuit breaker).

FIG. 7 is a change diagram of each phase current, each phase voltage, and interphase voltage in the case of the three-phase direct test, and FIG. 8 shows each phase current, each phase voltage, and interphase voltage by the above-mentioned conventional synthetic test method. It is a change diagram. Comparing the interphase voltage with reference to these figures, the interphase voltage is √2E at the maximum in the three-phase direct test, whereas it is the maximum in the synthetic test by the circuit configuration of FIG. It is 2.04E (= 1.22E + √2 / √3 × E). Therefore, it can be seen that the conventional synthetic test method is considerably severe in terms of conditions.

The present invention has been made in view of such a background, and an object thereof is a synthetic test method of a circuit breaker capable of performing highly equivalent verification without giving excessive stress and its realization. To provide a circuit.

[0012]

According to the synthetic test method of the present invention which achieves the above object, a voltage source circuit is connected in parallel to a cutoff phase of a circuit breaker under test, and a current source current supplied to the cutoff phase is cut off. In a method of superimposing a voltage source current from the voltage source circuit immediately before the moment and generating a transient recovery voltage in the interruption phase at the same time as interruption of the superimposed current, the voltage source circuit is tested immediately after interruption of the current source current. The circuit is characterized in that it is separated from the breaker phase of the circuit breaker and an AC voltage is applied to the breaker phase of the test breaker.

Further, a test circuit of the present invention which achieves the above object is a test circuit which realizes the synthetic test method according to claim 1, wherein a three-phase current for supplying a short-circuit current to the cut-off phase of the circuit breaker under test. Source circuit, an auxiliary circuit breaker inserted and connected between this current source circuit and the breaking phase of the test circuit breaker, the primary winding on the input side and the secondary winding on the output side of this auxiliary circuit breaker Each has a voltage source transformer connected thereto, and a voltage source circuit connected in parallel to the cutoff phase of the test circuit breaker via a switching switch for separation,
The isolation switch is opened immediately after the short circuit current is cut off, and an AC voltage is applied from the secondary winding of the voltage source transformer to the cutoff phase of the test breaker.

A resistor is inserted and connected between the output side of the auxiliary circuit breaker and the secondary winding of the voltage source transformer.

[0015]

[Function] The voltage source current is superimposed on the breaking phase of the test breaker immediately before the current source current (short circuit current) is interrupted, and immediately after the zero point of the superimposed current, the transient recovery voltage starts to be generated on the output side of the voltage source transformer. . However, since the voltage source current still flows through the test breaker at this point, the transient recovery voltage is almost shared by the resistor on the secondary side of the voltage source transformer. When the voltage source current reaches the zero point, the current is cut off and a transient recovery voltage is generated. The separation switch separates the voltage source circuit when the transient recovery voltage converges. As a result, an AC voltage is applied from the voltage source transformer to the breaking phase of the test breaker. Therefore, even in the case of the non-grounded system test, the transient recovery voltage of the cutoff phase does not have a constant value, and the voltage increase between the other phases is suppressed.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a synthetic test circuit for a circuit breaker according to an embodiment of the present invention. The same parts as those in the conventional circuit shown in FIG. 4 are designated by the same reference numerals.

In the present embodiment, as shown in FIG. 1, in the conventional circuit, a voltage source transformer 11 similar to the second and third breaking phases is provided between the first breaking phases of the auxiliary breaker 4, and further, A disconnecting switch 12 is inserted and connected between the first breaking phase of the test breaker 3 and the voltage source circuit 2.

Next, the operation of the synthesis test circuit having the configuration shown in FIG. 1 will be described with reference to FIGS. First, the separation switch 12 is closed, and the test is started in the same procedure as the conventional circuit. Point b in the first shut-off phase (see Figures 2 and 3)
At, the voltage source current is superposed from the voltage source circuit 2, and immediately after the zero point (point b ') of the superposed current, a transient recovery voltage starts to be generated at the output electrode of the voltage source transformer 11. However, at this time point, the voltage source current is still flowing in the test breaker 3 and the three-phase short-circuit grounding is being performed. Therefore, the transient recovery voltage is the resistor R ₁₁ connected to the secondary side of the voltage source transformer _11.
Will be almost shared.

When the voltage source current reaches the zero point (point c), the current is cut off, and the TRV 9 and the voltage source circuit 2 generate a transient recovery voltage.

A command is given to the separation switch 12 at a predetermined timing in advance so that the voltage source circuit 2 (current superposition circuit) is separated when the transient recovery voltage converges (point c '). An AC voltage is applied from the voltage source transformer 11 to the breaking phase of the test breaker 3 from which the voltage source circuit 2 is separated.

Therefore, even after the second and third phases are shut off, the voltage of each phase shows the same aspect as the case of the three-phase direct test for both the ground and the phase, and according to the conventional synthetic test method of this kind. The problem is solved.

[0023]

As is apparent from the above description, according to the present invention, the transient recovery voltage of the cutoff phase does not become a constant value even in the case of the non-grounded system test, and the voltage between the other phases is not recovered. It also has the effect of suppressing the voltage rise. This makes it possible to carry out highly equivalent synthetic tests without applying excessive stress.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a synthesis test circuit according to an embodiment of the present invention.

FIG. 2 is an operation timing chart of the synthesis test circuit according to the present embodiment.

FIG. 3 is a partially enlarged view of the operation timing chart of FIG.

FIG. 4 is a configuration diagram of a conventional synthesis test circuit.

FIG. 5 is an operation timing chart of a conventional synthesis test circuit.

6 is a partially enlarged view of the operation timing chart of FIG.

FIG. 7 is an explanatory diagram of states of each phase voltage, current, and interphase voltage by a direct test method.

FIG. 8 is a state explanatory diagram of each phase voltage, current, and interphase voltage according to a conventional synthesis test method.

[Explanation of symbols]

1 ... Current source circuit 2 ... Voltage source circuit 3 ... Test breaker 4 ... Auxiliary breaker 5, 6, 11 ... Voltage source transformer 7, 8, 9 ... Transient recovery voltage adjusting element (TRV) 10 ... Arc period extension circuit _{R 5, R 6, R 11} ... resistor 12 ... separation switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shunichi Arakawa 2-1,17 Osaki, Shinagawa-ku, Tokyo Stock company inside Meidensha (72) Inventor Teruichi Nagai 2-1-117 Osaki, Shinagawa-ku, Tokyo Shares Inside the company Meidensha

Claims (3)

[Claims] 1. A voltage source circuit is connected in parallel to a breaking phase electrode of a circuit breaker under test, and a voltage source current is superposed from the voltage source circuit immediately before a breaking instant of a current source current supplied to the breaking phase. In the synthetic test method of a circuit breaker that generates a transient recovery voltage in the relevant cutoff phase at the same time as the cutoff of the superimposed current, immediately after the cutoff of the current source current, disconnect the voltage source circuit from the cutoff phase of the test breaker A synthetic test method for a circuit breaker, characterized in that an AC voltage is applied to a circuit breaker phase. 2. A test circuit for realizing the synthetic test method according to claim 1, wherein the three-phase current source circuit supplies a short-circuit current to the breaking phase of the test breaker, the current source circuit and the test breaking. An auxiliary circuit breaker inserted between the circuit and the breaker phase, and a voltage source transformer in which the primary side winding is connected to the input side and the secondary side winding is connected to the output side of the auxiliary circuit breaker. And a voltage source circuit connected in parallel to the cutoff phase of the test circuit breaker via a separation switch, the separation switch being opened immediately after the short circuit current is cut off, and the two of the voltage source transformers being opened. A synthetic test circuit, wherein an AC voltage is applied from the secondary winding to the breaking phase of the circuit breaker under test. 3. The synthetic test circuit according to claim 2, wherein a resistor is inserted and connected between the output side of the auxiliary circuit breaker and the secondary side winding of the voltage source transformer.